Process of manufacturing steel.



STATE iii PAL ltiiit ii t @FFIQ HENRY D. HIBBABD, 03.? PLAINFIJ SIJ), NEW JERSEY.

PROCESS OF MANUFACTURINGSTEEL.

Specification of Letters Patent.

Application filed December 24, 1908.

No Drawing- T a an whom it may concern.

Be it known that I, HENRY l). Hnnmnn, a citizen of the United States of America, residing at Plainfield, in the county of Union and State of New Jersey, have in vented a certain new and Improved Process of Manufacturing Steel, of Which the following is a specification. The present invention relates to an iinproved process of manufacturing steel and its object is to expedite and cheapen the process of manufacturing steel from crude Iron, particularly in an open hearth :l'ur- 118136.

In some cases the present process may at One stage thereof involve the utilization of the calorific properties of the inetolloids in crude iron as described in my patent No. 885,248 granted April e1, 1908.

Broadly stated the present process contemplates the elimination from crude iron by oxid of iron at a t'cn'ipernture below thui of molten steel, oil the uietulloids coutniiuul therein which give the oxid of iron err therinic reactions and the subsequent troutment of this mass with oxid ot' iron at :1 higher temperature to eliminate the carbon to any desired degree for the productimi of steel. These treatments are carried out in separate vessels, the first in a closed vessel or reactor by which is inennt one with nv coul'inuous envelop and Wli'llolll'. passages for the admission of fuel or air, the only opcniiigs being for charging: nod discharging the vessel, and these being closuhlc, it proferred, during the reaction, and the second in afsteel furnace, prclcruhly of the open hearth type, the transfer to the steel tin--- naee being uccoiupnnied by the partial or I complete separation of the slap; formed during the first step. .lhe oxul ol iron cuiployed may be of any suitable type for iustance cinder richly charged with oxid) and it may be, introduced into either vessel in either the solid or the molten state.

For carrying out the process in all its variations 1t is preferable to utilize (l) a furnace for heating or melting the onid of iron. In certain cases this furnace Illly he dispensed with, as for instance when the crude iron has a suiiiciently high percentage ofsilicon to furnish by its heat of combustion a sufficient amount of heat to melt the QXid of iron, and When the oxid of iron is to be added to the steel. "furnace in the s lid f rm. (2) A closed reaction vessel,

preferably of the type described in my Patent 885,248 and (3) :1 steel furnace preferably of the open hearth typc,-hcated by fuel. electricity or any other suitable means.

The process may be carried out as follows: The reaction vessel and steel furnace being heated to their appropriate temperatures, viz. red and white heat respectively, a quantity of oxid oi iron at least suflicient For one charge of the reactor, is heated (melted if necessary) in the oxid furnace. A charge of molten crude iron is run into the reaction vessel, the heated oxid of iron intrmluced and the two thoroughly mixed in the reaction ves .l Further additions of oxid are made, it required, to complete the reaction, lvhon the crude-iron has been suflicicnlly refined and purified it is poured into n ladle nod taken to the steel furnace.

The steel furnace may have had previously introduced therein the oxid of iron which is to he utilized to oxidize the carbon of the churgrc coming from the reaction vessel. quantity of scrnp metal may also be intrmluccd to Form part of the charge, if dcsircil. lulu ihc stccl 'i'urnucc so charged, the uichil from the reaction vessel is poured, the slug lu ing; withhold in whole or in part for u' reason to he presently explained. rll'lcr the oxidisuliou and consequent elimination ol' the cnrhou to n silllicicnl' dcgrcc,

the charge is rr-udy to ho linishcd and drown ch" in (hc customary nmuncr. I prefer to introduce scvcrul charges from the reaction vcsscl lo the stccl furnace before the latter is d rawn oli", in each case accompanying the some with :1. fresh supply of oxid-introduccrl just hct'orc or just after the charge from the reaction vessel, so that the entire charge in the steel furnace is largely freed from carbon before the next charge from [he rein-lion rcsscl is introduced. This method otl' charging the steel furnace by degrees may be accomplished without undue cooling due to the consumption of heat in the elimination of carbon by oxid of iron since the entire heat of the furnace is conccnlrzitcd upon the added port of the charge and the blanket of slag is of the minimum practicable thickness.

The withholding of a part of the slag of the reaction vessel from the charge as introduced therefrom into the steel furnace, results in a decided advuntuge since the bulk of the silicon and-phosphorus of the crude iron are thus eliminated and the large quanventing the smaller pieces from reaching the metal at all, while the large pieces would have less contact with the metal. Furthermore such heavy slag would act as a blanket keeping the heat of the flame away from the metal to an undesirable, degree andso prolong the process. 3 It is to be understood however that it is desirable to introduce a portion of the slag from the reaction vessel into the steel furnace, since it will there supply part of the acid needed to prevent the stee furnace slagfrom becoming too infusible; it will also carry a portion of the oxid of iron needed in the steel furnace slag and thus reduce by so much the amount of oxid of iron necessary to be there added, and

it will further save the heat and time required to melt the slag-forming materials otherwise necessary. But the amount of slag so introduced is small since one of the features of the process is the maintenance of as thin a slag blanket in the steel furnace as is practicable to protect the metal from the free oxygen of the air introduced.

A further great advantage of the process arises from the relatively low temperature of the metal in the reaction vessel which favors the elimination of phosphorus from the metal while retarding the oxidation of the carbon. I

A third great advantage of the process where a plurality of charges from the reac-' tion vessel are introduced into the steel fur; nace, results from the fact that each charge of the metal from the reaction vessel is largely decarbonized' before the addition of the next charge and the operation of the steel furnace is thereby much hastened.

The expression exothermic react-ions is used to designate reactions which yield more heat than they consume so that there is an excess of sensible heat afforded by which the temperature of the mixture will be higher than otherwise.

The process described may be varied without departing from my invention, and I do not limit myself to the precise details or instrumentalities described in carrying out the same.

I claim as my invention:

1. In the process of making steel from crude iron, the addition of a quantityfof heated oxid of iron to a bath of crude iron to remove from the latter those elements 7 thereof which give an exothermic reaction with oxid of iron, the transfer of the iron nace and the subjection of the charge in said steel furnace to the action of a further quant-ity ofoxid of iron to oxidize the excess of carbon present by endothermic reaction, substantially as described.

crude iron, the addition of a quantity of heated oxid of iron to a bath of crude iron, in' a closed vessel at approximately its fusing temperature, to remove fromthe latter those elements thereof which give an 'exothermlc j -2. In the process of making steel from" y reaction with oxid of iron, the transfer of v the iron so purified together witha' portion of the slag of said reaction, to a suitablesteel furnace and the subjection of the charge in said steel furnace to external heat andto the action of a further quantity of oxid of iron to oxidize the carbon present by endothermic reaction, substantially as described.

3. In the process of making steel, the formation of a steel charge by introducing into a steel furnace successive charges of molten iron together with a portion of its molten iron has been subjected to the action ofoxid of iron to substantially eliminate the metalloids giving an exothermic reaction with said oxid of iron.

4.,In the process of making steel, the

formation of a steel charge by introducing into ,a, steel furnace successive charges of.

molten iron together with a predetermined portion of its slag from a reaction vessel in which said molten iron has been subjected to the action of oxid of iron to substantially eliminate the metalloids giying an exother- "mic reaction with said oxid of iron, and addinga quantity of oxid of iron with each charge in the steel furnace in order to eliminate the excess of carbon by the endothermic reaction of said oxid of iron and carbon under the influence of heat in said furnace.

'5. In the process of making steel, the

slag from a reaction vessel in which said formation of asteel charge by introducing into a steel furnace successive component charges of molten iron from which the sill-- con has previously been eliminated by reaction with oxid of iron, and eliminating in the steel furnace the greater part of the caroxid or iron to eliminate the silicon therefrom, the transfer of said silicon purified In testimony whereof I have signed my charge in molten condition together with a, name to this specification, in the presence of witnesses. HENRY D. HIBBARD.

Witnesses:

WALTER ABBE, WILLIAM ABBE.

predetermined proportion of its slag to a two subscribing steel furnace and the subjection of said charge in the steel furnace to reaction with a further quantity of oxid of iron to eliminote the carbon therefrom. 

